STATE COLLEGE, Pa. (AP) - While the offensive overhaul gets the most attention this spring at Penn State, coach Bill O'Brien is making a few tweaks on defense, too.

``Aggressive' is the word heard most from players when asked to describe the philosophy under Happy Valley newcomers O'Brien and defensive coordinator Ted Roof.

``It's going to be a multiple aggressive defense. We're going to be flying around showing a lot of different looks,'' linebacker Michael Mauti said this week.

Safety Stephen Obeng-Agyapong has even loftier aspirations.

``One of our goals is to be one of the most aggressive defenses in the nation this year,'' the junior said.

Not that the Nittany Lions were slouches on defense under O'Brien's predecessor, the late Joe Paterno. The program did acquire the moniker ``Linebacker U.,'' after all, during Paterno's 46-year tenure. Last season, the Nittany Lions were first in scoring defense (16.8 points) but sixth in total defense (323.9 yards) in the Big Ten.

But Paterno and his defensive coordinator, Tom Bradley, employed a ``bend-but-don't break'' scheme that relied primarily on four-man rushes to get to the quarterback with the secondary dropping back in coverage. Opposing offenses tried to exploit Penn State with short passes in space.

And for a second straight year, Penn State finished last in the league in red zone defense, allowing scores on 91 percent of possessions inside the 20 each of the last two seasons.

So fickle fans anxious to see improvement might enjoy the promise of different defensive wrinkles out of the base four-down scheme.

``Everyone's getting used to the new coaching staff and learning everything that has been thrown at us,'' defensive tackle Jordan Hill said. ``We just can't wait to keep the train moving.''

Hill figures to be one of the leaders of the defense next season along with linebackers Gerald Hodges and Mauti, who is limited this spring as a precaution following last year's season-ending injury to his left knee.

They're three key returnees that should lend some continuity to the defense to go with the two holdovers from Paterno's staff, defensive line coach Larry Johnson and linebackers coach Ron Vanderlinden. That should help the rest of the defense get used to incorporating schemes with wrinkles like more disguised looks.

``It's just the spring. We're just trying to keep things a little more simplified,'' said Mauti, who is expected to return to full workouts by the fall. ``There are a lot of places this defense can go in terms of disguises.''

The most pressing concern this spring for Roof is finding four new starters in the secondary to replace last season's senior-laden defensive backfield. There is some experience after Willis, Obeng-Agyapong and rising sophomore Adrian Amos all saw time in key reserve roles.

Cornerback Stephon Morris was also a part-time starter last year and played a healthy number of snaps, while speedy Curtis Drake has been moved from receiver to cornerback.

The other notable difference on defense has to do with terminology. The ``Hero'' position on the depth chart under Paterno is back to being called the position actually entails - strong safety.

``We're not talking about apples and oranges here. You still have to fly to the ball and make tackles,'' Mauti said about the changes.